The invention relates to a tyre building drum for building an unvulcanised tyre using rubber tyre components, wherein the tyre building drum comprises a central drum shaft and two drum halves arranged at least almost substantially symmetrical with respect to the centre of the tyre building drum and around the drum shaft.
Such a tyre building drum is known from EP-B1-1.439.054. Said known tyre building drum comprises a base spindle for the folding units, around which base spindle a hollow second spindle for the bead ring core clamping units is arranged coaxially. The base spindle can be coupled to the hollow second spindle by means of a connectable coupling, so that both spindles can be coupled to each other (for moving the entire drum half) and uncoupled from each other. Although compared to other tyre building drums using a pneumatic drive for the folding arm carrier bodies said known tyre building drum due to use of particularly the base spindle provides a considerable improvement regarding the synchronous lifting of two folding arm units, the known tyre building drum has a few drawbacks. For instance the connectable coupling does not only constitute a relatively expensive and complicated additional part, said connectable coupling is also difficult to repair in case of a failure. Due to the use of the two coaxial spindles the tyre building drum is also relatively long and bulky.